Ottawa bathroom renovations.
Built to last decades, not trends.

The City of Ottawa decides when a bathroom needs a building permit. The Electrical Safety Authority and the Ontario Building Code set what the inspectors check. The age of your house decides what turns up behind the wall.

1. 1

   Moving plumbing or walls needs a City of Ottawa building permit.

   The City of Ottawa's "Do I need a building permit?" page lists "alterations, additions or extensions to a plumbing system (except replacing existing fixtures)" as permit work, along with adding or removing walls. The same page exempts replacing bathroom cabinets when the plumbing fixtures stay in the same location, new flooring, and painting. A toilet swapped in place needs no building permit. Move it across the room and it does.

   Older neighbourhoods have one exception to watch. The City says designated heritage buildings and buildings in a Heritage District Overlay are not subject to the exemptions, so even a cabinet-and-floor job there starts with a call to a Building Client Service Centre.

   Next stepHow an application is filed, reviewed and inspected: our guide to Ottawa building permits.
2. 2

   Electrical work needs an ESA notification, separate from the permit.

   The Electrical Safety Authority, which administers the Ontario Electrical Safety Code, states that all outlets within 1.5 metres of a sink must be GFCI-protected. In a bathroom that means the vanity outlet at minimum.

   ESA also says a building permit is not the same as an electrical notification, and a job may need both. A heated floor, a new fan circuit or moved lighting gets filed with ESA before the work starts, by the Licensed Electrical Contractor or by a homeowner doing their own wiring.

3. 3

   The exhaust fan has a code minimum, and it is low.

   Ontario's 2024 Building Code took effect on 2025-01-01. Its Article 9.32.3.7 sets a minimum of 50 cfm for a supplemental bathroom exhaust fan, according to the Heating, Refrigeration and Air Conditioning Institute of Canada's comparison of the 2012 and 2024 codes.

   That 50 cfm is what passes inspection. Our own specification, in mistake 2 further down this page, is 80 to 110 CFM with a humidistat or timer, because an Ottawa bathroom has to clear shower steam through a winter when nobody opens a window.

4. 4

   Code-minimum waterproofing is tile, not a membrane.

   The Ontario Building Code's waterproof-finish article, 9.29.2.1, calls for a waterproof finish at least 1.8 m above the floor in a shower stall and 1.2 m above the rim of a tub that has a shower, as the City of Markham's builder tip on the 2012 code sets out. The next article accepts ceramic tile as that finish, and Article 9.29.10.4 asks for the tile to sit on moisture-resistant backing.

   So grout-jointed tile on water-resistant board meets the minimum. Grout is porous, which is why every Dream Touch shower gets a Schluter-Kerdi membrane under the tile, one layer more than the code asks for.

5. 5

   Older Ottawa houses hide three things behind a bathroom wall.

   Knob-and-tube wiring comes first. ESA dates it to homes wired from the early 1900s to the 1940s. The 2021 Ontario Electrical Safety Code deleted its installation rules without making that retroactive, so existing runs are legal, but ESA notes that many insurers will not provide or renew coverage on a home that has it. An open bathroom wall is when that circuit is easiest to reach.

   Old supply and drain lines are next. HomeStars' Ottawa guide notes that heritage homes in the Glebe, Sandy Hill and Rockcliffe Park often have older cast-iron or copper plumbing that costs more to work around. Our own guide to budgeting a bathroom renovation adds that pre-1980 houses sometimes have galvanized steel supply lines corroded to half their original diameter.

   The third is the water service itself. The City of Ottawa says homes potentially affected by a lead water service pipe are typically those built before 1958. The only visible stretch runs between the basement floor and the water meter, and the City suggests scratching it with sandpaper to expose bare metal. It takes a minute while the plumber is already on site.

6. 6

   Winter decides where the fan duct can run.

   A bathroom fan pushes warm, wet air through a duct, and in an Ottawa January that duct often crosses a cold attic. The U.S. Department of Energy's Building America Solution Center, run by Pacific Northwest National Laboratory, says to insulate the duct to minimize condensation and to vent the fan directly outside, not into an attic or crawlspace.

   It also recommends a terminal on the side wall slightly below the fan, so the duct slopes down and condensation drains away from the housing.

   Our budgeting guide flags the older version of this problem: a fan that was vented into the attic instead of outside. Rerouting that duct adds labour, so it belongs in the quote before demolition, not in a change order after it.

If you are asking what to avoid when renovating a bathroom, start with these seven. Every single one of these mistakes shows up in the bathrooms we redo for clients who went with the wrong contractor. Avoid these and your bathroom will last 30+ years.

1. 1

   Skipping proper waterproofing to trim the quote.

   The contractor uses green board + waterproof paint instead of a proper membrane. Grout cracks at year 2, black mould appears behind walls at year 5. Remediation then costs far more than doing it right the first time, often a full gut-and-rebuild of the wet wall.

   Dream Touch fixSchluter-Kerdi membrane on every wet wall, with no exceptions.
2. 2

   Undersizing the exhaust fan.

   Builder-grade fans move 50 CFM. A proper Ottawa bathroom needs 80–110 CFM with a humidistat or timer. Without that you get lasting humidity, peeling paint, fogged mirrors and moisture inside walls.

   Dream Touch fixContinuous-duty fans sized to cubic footage + auto humidistat control.
3. 3

   Choosing tile that looks great in the showroom but fails at home.

   Polished stone scratches, honed marble absorbs soap, and large-format tile lippage ruins the visual. Selection errors mean tearing out and re-tiling, one of the most expensive redos in a bathroom.

   Dream Touch fixTile consultation with onsite lighting test. We specify tile for how it performs as well as how it looks.
4. 4

   Going with the cheapest quote without asking about subfloor.

   Cheap quotes assume the subfloor is fine. Then demo reveals rotted OSB and the "surprise" change order arrives, a hidden cost that should have been priced up front.

   Dream Touch fixWe inspect subfloor at design stage with a moisture meter. Subfloor replacement (if needed) is priced in the original quote.
5. 5

   Relocating plumbing "because it's easy."

   Moving a toilet drain 4 feet sounds minor, but it means opening the ceiling below, rerouting the vent stack, and re-inspecting. Adds significant labour and roughly 3 weeks if not planned.

   Dream Touch fixOur plumber meets you at design stage to confirm what can and can't be moved, before the contract is signed.
6. 6

   Forgetting to upgrade electrical to current code.

   Older Ottawa homes have 15-amp bathroom circuits with no GFCI. Modern fans, heated floors, and vanity lights overload them. The code inspection fails and the project stalls 2 weeks.

   Dream Touch fixFull electrical assessment at design stage. Panel and circuit upgrades priced into the contract.
7. 7

   Picking finishes after demolition starts.

   Tile, vanity, and fixture lead times in Ottawa are 4–12 weeks. Starting demo before materials arrive means dead time mid-project. Adds 3–6 weeks.

   Dream Touch fixWe don't swing a hammer until every material is delivered to our warehouse. Your contract ties the start date to material delivery.